Patent application number | Description | Published |
20080272288 | Method and apparatus for scaling intensity data in a mass spectrometer - A method includes: accumulating ions having a plurality of m/z values in an ion trap during a time interval; deriving from the accumulated ions a respective intensity value for each of the m/z values; and adjusting each of the intensity values as a function of the time needed by the ion trap to begin collecting ions with the corresponding m/z value. According to a different aspect, an apparatus includes a first portion with an ion trap, and a second portion. The second portion causes the ion trap to accumulate ions with a plurality of m/z values during a time interval, derives from the accumulated ions in the ion trap a respective intensity value for each of the m/z values, and adjusts each of the intensity values as a function of the time needed by the ion trap to begin collecting ions with the corresponding m/z value. | 11-06-2008 |
20090032702 | Method and Apparatus for Selectively Providing Electrons in an Ion Source - An electron source can selectively provide a first stream of electrons that travels in a direction along an imaginary line to a location remote from the electron source, or a second stream of electrons that travels in the direction along the line to the location. The electron source includes a first electron emitter for selectively emitting electrons for the first stream, and a second electron emitter for selectively emitting electrons for the second stream. A different aspect relates to a method for operating an apparatus having an electron source that includes first and second electron emitters. The method includes selectively producing a first stream of electrons that travels from the first electron emitter in a direction along an imaginary line to a location remote from the electron source, or a second stream of electrons that travels from the second electron emitter in the direction along the line to the location. | 02-05-2009 |
20090194680 | Method and Apparatus for Normalizing Performance of an Electron Source - A method for operating a mass spectrometer includes determining a first performance characteristic while operating the mass spectrometer with a first electron emitter, storing first information relating to the first performance characteristic, determining a second performance characteristic while operating the mass spectrometer with a second electron emitter, storing second information relating to the second performance characteristic, and thereafter switching from operation using the first electron emitter to operation using the second electron emitter. The switching includes using the first and second information to normalize performance of the second electron emitter after the switching relative to performance of the first electron emitter before the switching. | 08-06-2009 |
20090212209 | Optimization of Excitation Voltage Amplitude for Collision Induced Dissociation of Ions in an Ion Trap - Collision induced dissociation of precursor ions in an ion trap is performed by determining a predicted fragmentation-optimized excitation voltage amplitude based on an indicator of damping gas pressure, such as a damping gas flow rate, and optionally other parameters including precursor ion m/z and an indicator of the Mathieu parameter q. The excitation voltage may then be applied to electrodes of the ion trap in steps of increasing amplitude, wherein at least one of the amplitudes corresponds to the predicted optimum value. Application of the excitation voltage in this manner produces favorable fragmentation efficiencies over a range of operating parameters and for ions of differing chemical properties. | 08-27-2009 |
20090242747 | Removable Ion Source that does not Require Venting of the Vacuum Chamber - A method and apparatus of combining an ion volume, a lens stack, and an ion optic that similarly cooperates with a detached multipole ion guide is herein incorporated into a single sub-assembly that can be removed from a mass spectrometer instrument without venting. Such an arrangement allows an operator to clean all parts of the ion path that get contaminated in normal operation, reassemble and reinsert in a timely manner and then pump down to an acceptable vacuum without having to vent the system. | 10-01-2009 |
20100148063 | Differential-Pressure Dual Ion Trap Mass Analyzer And Methods Of Use Thereof - A dual ion trap mass analyzer includes adjacently positioned first and second two-dimensional ion traps respectively maintained at relatively high and low pressures. Functions favoring high pressure (cooling and fragmentation) may be performed in the first trap, and functions favoring low pressure (isolation and analytical scanning) may be performed in the second trap. Ions may be transferred between the first and second trap through a plate lens having a small aperture that presents a pumping restriction and allows different pressures to be maintained in the two traps. The differential-pressure environment of the dual ion trap mass analyzer facilitates the use of high-resolution analytical scan modes without sacrificing ion capture and fragmentation efficiencies. | 06-17-2010 |
20110143451 | Method of Operating a Reagent Ion Source - A method is disclosed for operating a chemical ionization-type (CI-type) source to generate reagent ions for mass spectrometry experiments, such as electron transfer dissociation (ETD) reagent ions. The method includes periodically reversing current flow in the thermionic filament employed to produce the electron stream. Periodic reversal of the filament current avoids or reduces the problem of carbonaceous growth formation associated with prior art reagent ion sources. | 06-16-2011 |
20110315866 | Forward and Reverse Scanning for a Beam Instrument - A quadrupole mass spectrometer alternates between increasing mass and decreasing mass scans for the purpose of decreasing inter-scan delays. By alternating increasing and decreasing mass scans, the next scan starts where the last scan ended reducing the settling time required. Backsteps may be eliminated by scanning the RF and DC non-linearly. | 12-29-2011 |
20120032072 | Method and Apparatus for Automatic Estimation of Detector Gain in a Mass Spectrometer - A method and apparatus involve: performing a plurality of analytical scans during normal operation of a mass spectrometer having a detection section, wherein data is generated during the analytical scans in a manner that includes use of the detection section; and automatically evaluating the data from the analytical scans to monitor whether an actual gain of the detection section changes over time. | 02-09-2012 |
20130152666 | Gas Chromatograph Column Markings to Determine Length - A gas chromatograph column is marked with a code that allows an operator or machine to accurately determine the distance between two points on the column by comparing markings at the two points on the column. The code may be human or machine readable. | 06-20-2013 |
20130214147 | Apparatus and Method for Inhibiting Ionization Source Filament Failure - An ion source apparatus for a mass spectrometer comprises a refractory metal filament operable to provide a flow of electrons by thermionic emission; an electrical current source electrically coupled to the filament for heating the filament; a vacuum chamber enclosing the filament; an ionization volume within the vacuum chamber capable of receiving the flow of electrons; a source of an oxygen-providing gas or gases; a restrictive fluidic coupling to the source of oxygen-providing gas or gases; and a gas conduit fluidically coupled to the restrictive fluidic coupling, the restrictive fluidic coupling and conduit operable to provide a flow of the oxygen-providing gas or gases into the vacuum chamber so as to maintain a partial pressure of said gas or gases within the vacuum chamber that is sufficiently high so as to inhibit the otherwise formation of a carbonaceous growth on the filament in the presence of a gaseous carbon-containing material. | 08-22-2013 |